In which reference (book or paper) can I find the variation of Gibbons-Hawking boundary term ((-h)^(1/2)*K) with respect to induced metric (h_{ab})?

I mean how can I obtain \partial ((-h)^(1/2)*K)/ \partial h_{ab} where K is extrinsic carvature and h_{ab} is induced metric?

09 September 2015 9,037 4 View